This invention relates to new and useful antibacterial agents, and to their chemical methods of preparation. More specifically, it is concerned with a novel class of cephalosporin derivatives which possess broad spectrum antibacterial activity against both Gram-positive and Gram-negative microorganisms. In particular, the compounds of the invention constitute a series of 7-(.alpha.-aminophenylacetamido)- and 7-(.alpha.-hydroxyphenylacetamido)-.DELTA..sup.3 -cephem derivatives with a thiomethyl moiety attached to the cepham nucleus at the 3-position of the molecule.
In the past, various attempts have been made by numerous investigators in the field of chemotherapy to obtain new and better antibacterial agents. For the most part, these efforts have involved the synthesis and testing of various new and heretofore unavailable organic compounds, particularly in the area of semisynthetic antibiotics like the cephalosporin derivatives. For instance J. S. G. Cox et al. in U.S. Pat. No. 3,278,531 and German Offenlegungschrift No. 2,262,262 to Fujisawa both broadly disclose various 7-(D-acylamino)-3-(heterocyclic)thiomethylceph-3-em-4-carboxylic acid derivatives alleged to be useful for these purposes. However, in the search for still new and more improved antibacterial agents, little is know about the effect of certain particular novel heterocyclic thiomethyl moieties on compounds of this type, especially when the heterocyclic nucleus bears one of a series of certain speciified substituents.